In a palatial mansion on Long Island, a lone, well-dressed millionaire played in an all-out performance by Leonardo DiCaprio, presides virtually unseen over a bacchanal of benumbed excess, the avatar of an age of heedless self-indulgence and greed.

Ah, so the 3-D version of “The Great Gatsby” is being re-released? Not quite.

In “The Wolf of Wall Street,” Martin Scorsese’s big, bravura, maddeningly uneven indictment of the extreme financial depredations that characterized the 1990s, DiCaprio plays Jordan Belfort, a real-life swindler and penny-stock con man who made more than $100 million off of unwitting investors. The Queens-born Belfort may embody the same ambition and shadowy ruthlessness as F. Scott Fitzgerald’s self-made anti-hero, but he has none of his subtlety or allegorical heft. There’s no enigmatic green light goading Belfort on in “The Wolf of Wall Street,” other than the unseen internal one telling him to go, go, go and get more, more, more.

More, in this case, doesn’t just mean money – although in one of Belfort’s several speeches to his employees, delivered in a style suggesting Henry V combined with a touch of Catskills tummler – he suggests that whatever problems they may have, they should solve them by getting rich. As “The Wolf of Wall Street” makes clear from its first aggressive, whipsawing moments, Belfort is the ultimate empty vessel, a man who can never get enough of anything, whether it’s sex or drugs or validation from the audience he addresses by way of near-constant narration, occasionally breaking the fourth wall for a contemptuous tutorial in Darwinian finance.

Belfort is such a thoroughly loathsome character it makes “The Wolf of Wall Street” difficult to process as art, much less entertainment. There’s no doubt Scorsese – working with screenwriter Terence Winter, cinematographer Rodrigo Prieto and longtime editor Thelma Schoonmaker – is still working at the top of his game, his sheer technical chops and exuberant commitment exerting an insistent, sleeve-tugging pull.

Juxtaposing blues and Afro-pop riffs with shiny nouveau-riche settings and at least two astonishing set pieces, Scorsese evinces the same canny eye and ear that make his movies compulsively watchable, regardless of who or what they’re about. Only a filmmaker of his prowess and infectious energy can make three hours zip by this fast.

But in “The Wolf of Wall Street,” the film’s nominal subjects – Belfort’s ignominious rise (did he ever really fall?) and the gluttonous underbelly of capitalism he represents – aren’t particularly interesting, or new. When Belfort joins with his future partner Donnie Azoff (Jonah Hill), when he marries his stunning second wife Naomi (the angel-faced, fiery-eyed Margot Robbie), when he finally comes under the scrutiny of Patrick Denham (Kyle Chandler) an even-keel FBI agent, none of those relationships ever manages to be fully realized. Like DiCaprio’s, they’re superb, even brave performances in search of somewhere to go, go, go.

Instead, “The Wolf of Wall Street” remains one-note even at is most outre, an episodic portrait of rapaciousness in which decadence escalates into debauchery escalates into depravity – but, miraculously, not death. It’s a movie composed of several memorable moments – Matthew McConaughey’s deranged Tuvan throat singing as Belfort’s early mentor; a spectacular and cosmically unjust rescue at sea; a tawdry rampage through Las Vegas that costs $2 million in hookers, drugs and hotel repairs; Belfort’s degenerate office parties. The film’s centerpiece is a Keaton-esque sequence in which DiCaprio delivers a druggy feat of physical acting that’s both appalling and viciously, viscously funny.

But to what end? “The Wolf of Wall Street” doesn’t implicate the audience in Belfort’s desires, the way “Goodfellas” seduced viewers with its intimate, textured vignettes of Henry Hill’s life in the mafia.

Belfort is too scuzzy, the material culture he inhabits too bland and superficial, to create that kind of vicarious sympathy. But nor does the film ever empower its saner voices to give Belfort an adequate dramatic foil. (A line from Belfort’s father about “chickens coming home to roost” is especially lame: Gee Dad, ya think?) Chandler’s clean-cut FBI agent would have been the perfect Javert to Belfort’s monotonous amorality. As it is, he gets only one or two substantive scenes, one being a subway ride home that speaks volumes for being wordless and relatively brief.

That meaningful, eloquent moment notwithstanding, “The Wolf of Wall Street” maintains an oddly equivocating ethical stance throughout its vertiginous slide through the muck. On one hand, the filmmakers suggest Belfort’s most dehumanizing behavior is what undergirds every Wall Street firm, that behind those stentorian ads and Forbes profiles are just a bunch of tacky, boiler-room bros with their snouts in the trough. But in the final analysis, they pull their punches on Belfort – who actually appears in the final scene of the movie, wielding, what else, a microphone (reportedly, he has yet to pay up fully on the $110 million he owes in restitution to his victims).

In “Goodfellas,” which still reigns supreme as Scorsese’s finest plunge into the low life, the film ends on that teasingly ambiguous shot of Ray Liotta’s Mona Lisa smile. In “The Wolf of Wall Street,” Scorsese turns his gaze on the audience itself, suggesting that it’s our own avarice – or at least fatal naivete – that creates monsters like Belfort. OK, but . . . really? Belfort and his more well-heeled but equally crooked colleagues at white-shoe firms cooked up what may be the largest transfer of wealth in human history. And it’s schmoes like us that “The Wolf of Wall Street” holds accountable? That laughing sound you hear just out of eye-shot may well be Belfort, having the last howl.